Could you please share the screenshot of your Lightroom facebook export settings?
Which version of Lightroom do you have ?
hi again !!
Settings i have testet is :
JEPG - sRGB - quality 80 - filsize 100k - longest egde 960 pix - 72ppi - don´t enlarge - sharping for screen - normal
have also tried 650 k - longest egde 2048 and 72ppi , seem better but still not ok !
would suggest you not to limit the file size and keep the quality at 100.
How big is the image in pixels (width and height) before you export?